. >> reporter: until years later technology made day to night possible. >> you know, you can just see the way the light moves. it's pretty exciting. i love when the lights come up, you know. >> reporter: remember central park in the fall? back at his studio in connecticut, the first thing steven wilkes has to do is decide literally where to draw the line. where day ends and night will begin. in the final print. >> you can actually see it as time changes. >> reporter: the next step is to look at everyone of the images he shot, collect his favorites and then digitally fit them together like puzzle pieces. you could go blind looking at 1400 of those. >> you're looking for some small, tiny nuanced detail. >> reporter: like the brides. the brides started to evolve. i mean basically i saw one in the morning. midday. i mean they literally were showing up all day long. >> reporter: here they all are in the finished photograph. >> it was really kind of a moment like a where's waldo. as i ket shooting i kept noticing another bride here. >> reporter: what took that one october day to shoot took